SkyEye

Welcome to SkyEye, your guide to this month's celestial events. All dates are based on Universal Time (UT).

The Sun and Moon

There are no eclipses this month. Earth gets it best glimpse of the Sun's north pole on 8 September. The equinox occurs on 23 September, marking the beginning of autumn in the northern hemisphere and the start of spring in the south. As seen from the Earth, the Sun is moving from the constellation Leo to the constellation Virgo.

The phases of the Moon are

Last Quarter : 2 September
New : 9 September
First Quarter : 17 September
Full : 25 September

The Moon is at perigee on 2 September, at apogee on 16 September, and at perigee again on 28 September.

The Moon occults two planets and two first-magnitude stars in September. Aldebaran glides behind the limb of the Moon on the second day of the month at 22 UT in a night-time event that can be seen from northern Asia. Like last month, the North Pole gets to see an occultation of Regulus. This daytime event occurs on 8 September. Like the previous five months, Neptune and Uranus are occulted a day apart. Neptune goes first on the 20 September at 22 UT. This is visible during darkness in the Atlantic and north Africa. The occultation of Uranus the following day at 20 UT follows a similar pattern, being visible in the north Africa and the Middle East during the hours of darkness. Finally, Aldebaran disappears behind the Moon for the second time this month on 30 September. Observers in northeastern Canada and Greenland have an opportunity to witness this event at 3 UT.

The Planets

The word planet is derived from the Greek word for "wanderer." Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars.
Mercury
Mercury reaches superior conjunction on 8 September and thus is too close to the Sun to be seen this month. Mercury can be found in the constellations of Leo and Virgo.
Venus
Now the "morning star," Venus soars high in the morning sky for northern observers but is considerably lower in the east for early-risers in the southern hemisphere. On 9 September the planet resumes prograde motion and on 25 September, reaches its maximum brilliancy with an apparent magnitude of -4.6. Venus can be found in the constellations of Cancer and Leo.
Mars
Mars can be found very close to the bright star Antares, providing an excellent opportunity to compare the red hues of our neighboring planet with that of the ruddy star. The red planet sets late in the evening in the constellations of Libra, Scorpio, and Ophiuchus.
Jupiter
The largest of the planets rises in the small constellation of Aries just as Mars sets in the west.
Saturn
Saturn rises just after Jupiter and also can be found in the constellation of Aries.
Uranus
Uranus is up most of the night with Neptune in the constellation Capricornus. Uranus is occulted by the Moon on 21 September.
Neptune
Neptune is falling behind Uranus after their triple conjunction in 1993, but they are still found close together in the sky. Like Uranus, Neptune also is occulted by the Moon, this time on 20 September. The blue planet is up nearly all night and can be found in the constellation of Capricornus.
Pluto
Pluto sets around midnight in the constellation Ophiuchus. However, because it is so small and faint, a large telescope is always needed to see it.

Minor Planets, Comets and Meteors

Minor Planets
A number of interesting minor planets populate the solar system.
Comets
There are no periodic naked-eye comets visible this month, but comet 10P/Tempel 2 makes its 25th visit to the inner solar system since its discovery in 1873 by Wilhelm Tempel. The comet reaches perihelion on 8 September and may become as bright as tenth magnitude, meaning that you will need a telescope to see it as it moves from Ophiuchus to Sagittarius to Microscopium.
Meteors
There are two major meteor showers this month. The alpha Aurigids peak on the first day of the month and the delta Aurigids on 9 September. The Moon is approaching new and so should not provide much interference for these showers.

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union (IAU) recognizes 88 different constellations. The brightest stars as seen from the Earth are easy to spot but do you know their proper names? With a set of binoculars you can look for fainter objects such as nebulae and galaxies or some of the closest stars to the Sun.

Descriptions of the sky for observers in both the northern and southern hemispheres are available for the following times this month. Subtract one hour from your local time if daylight savings time is in effect. (Note: These times are approximate.)

Northern Hemisphere : 45° N

Southern Hemisphere : 30° S

For More Information...

Blue moons, eclipses, the dates of Easter and much more can be found at the Interactive Astronomy Pages. For more information about the objects and events described in SkyEye, visit these astronomy-related sites.

Credits

Much of this information can be found in this month's issue of Sky & Telescope and in other fine amateur astronomy magazines available in your local bookshop. Another excellent source is the current edition of the Astronomical Calendar by Guy Ottewell and published by the Universal Workshop at Furman University.

The image of the Sun in the SkyEye banner is courtesy of the SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA.

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